1. Field of the Invention
This invention relates to a drying shelf structure which is adapted to be arranged in a drying chamber to effectively dry matter, and more particularly to a shelf structure for drying sacked matter which is used for drying particulate matter charged in an air-permeable sack.
2. Description of the Prior Art
Conventionally, various kinds of drying techniques such as, for example, drying utilizing hot air due to the combustion of petroleum, drying air dehumidified by means of a refrigerator and the like have been used for drying agricultural and marine products stored in various sizes of drying chambers. In order to effectively carry out the drying, the conventional drying techniques each require the above-described hot air or dehumidified air (hereinafter referred to as "drying air") to be constantly flowed in a drying chamber and uniformly contacted with the surface of matter to be dried.
In order to meet such requirements, the conventional drying techniques employ a system wherein a drying chamber is partitioned by means of a plurality of horizontal wire mesh shelves vertically arranged at suitable intervals, on which matter to be dried is put, or the matter is suspended from a ceiling of the drying chamber at suitable intervals, so that it may be contacted with the drying air as uniformly as possible.
Also, the conventional drying techniques fail to effectively dry sacked matter or matter charge in an air-permeable sack. The term "matter to be dried" used herein indicates, for example, various kinds of grains, plant seeds and the like. Also, the term "air-permeable sack" used herein indicates a sack formed of a chemical fiber woven fabric or non-woven fabric, a natural fiber woven fabric, various kinds of net materials, or the like so as to exhibit air-permeability.
More particularly, the conventional techniques permit drying air to be supplied to the surroundings of sacked matter stored in a drying chamber but fail to cause it to enter the interior of the sacked matter even when a sack is air permeable, so that it may not be uniformly dried. This is remarkable particularly when sacked matter is stackedly placed. Accordingly, the drying of sacked matter has been obliged to be carried out by taking out the matter from a sack and spreading it or charging it in a rotary drum to dry it. The so-dried matter is recharged in the sack.